Merge pull request #41655 from zoecarver/spec-as-base-class

[cxx-interop] Make sure to use the cannonical base class type.

Author: zoecarver

lib/IRGen/GenStruct.cpp

@@ -338,16 +338,18 @@ namespace {
 
       if (auto cxxRecord = dyn_cast<clang::CXXRecordDecl>(ClangDecl)) {
         for (auto base : cxxRecord->bases()) {
-          auto baseRecord = cast<clang::RecordType>(base.getType())->getDecl();
+          auto baseType = base.getType().getCanonicalType();
+
+          auto baseRecord = cast<clang::RecordType>(baseType)->getDecl();
           auto baseCxxRecord = cast<clang::CXXRecordDecl>(baseRecord);
 
           if (baseCxxRecord->isEmpty())
             continue;
 
           auto offset = layout.getBaseClassOffset(baseCxxRecord);
           auto size =
-              ClangDecl->getASTContext().getTypeSizeInChars(base.getType());
-          fn(base.getType(), offset, size);
+              ClangDecl->getASTContext().getTypeSizeInChars(baseType);
+          fn(baseType, offset, size);
         }
       }
     }
@@ -458,8 +460,14 @@ namespace {
 
       unsigned baseOffset = 0;
       if (auto cxxRecord = dyn_cast<clang::CXXRecordDecl>(ClangDecl)) {
-        baseOffset =
-            std::distance(cxxRecord->bases().begin(), cxxRecord->bases().end());
+        baseOffset = llvm::count_if(cxxRecord->bases(), [](auto base) {
+          auto baseType = base.getType().getCanonicalType();
+
+          auto baseRecord = cast<clang::RecordType>(baseType)->getDecl();
+          auto baseCxxRecord = cast<clang::CXXRecordDecl>(baseRecord);
+
+          return !baseCxxRecord->isEmpty();
+        });
       }
 
       // Otherwise, project from the base.

test/Interop/Cxx/class/inheritance/Inputs/fields.h

@@ -46,3 +46,12 @@ struct NonTrivialHasOneField {
 struct NonTrivialDerivedFromAll : NonTrivialHasOneField, NonTrivialDerivedWithOneField {
   int f = 6;
 };
+
+// Templates:
+
+template<class T>
+struct ClassTemplate {
+  T value;
+};
+
+struct DerivedFromClassTemplate : ClassTemplate<int> {};

test/Interop/Cxx/class/inheritance/Inputs/functions.h

@@ -49,3 +49,12 @@ struct DerivedFromDerived : Derived {
 };
 
 struct DerivedFromNonTrivial : NonTrivial {};
+
+struct EmptyBaseClass {
+  const char *inBase() const { return "EmptyBaseClass::inBase"; }
+};
+
+struct DerivedFromEmptyBaseClass : EmptyBaseClass {
+  int a = 42;
+  int b = 42;
+};

test/Interop/Cxx/class/inheritance/fields.swift

@@ -52,4 +52,10 @@ FieldsTestSuite.test("Fields from derived from non trivial") {
   expectEqual(mutable.f, 48)
 }
 
+FieldsTestSuite.test("Derived from class template") {
+  var derived = DerivedFromClassTemplate()
+  derived.value = 42
+  expectEqual(derived.value, 42)
+}
+
 runAllTests()

test/Interop/Cxx/class/inheritance/functions.swift

@@ -69,4 +69,10 @@ FunctionsTestSuite.test("base member from derived from non trivial") {
   expectEqual(String(cString: dnt.inNonTrivialWithArgs(0, 1)!), "NonTrivial::inNonTrivialWithArgs")
 }
 
+FunctionsTestSuite.test("non-empty derived from empty class") {
+  let derived = DerivedFromEmptyBaseClass()
+  expectEqual(String(cString: derived.inBase()!), "EmptyBaseClass::inBase")
+  expectEqual(derived.b, 42)
+}
+
 runAllTests()